NPS: 9th Yosemite Camper Got Hantavirus

Deer mice (Peromyscus maniculatus) are implicated as carriers of hantavirus pulmonary syndrome (HPS) in Yosemite and other parts of the U.S. Photo from Centers for Disease Control and Prevention.

Another person was sickened by hantavirus traced to Yosemite National Park, the latest in an outbreak that has grown to nine cases and has killed three visitors since mid-June, the Los Angeles Times reported.

The latest case, which sickened a California resident, is believed to have originated in one of Curry Village’s signature tent cabins in early July, park spokesman Scott Gediman said. A total of eight cases have been linked to the insulated signature tent cabins; the other to the High Sierra Loop that connects Yosemite Valley with Tuolumne Meadows and other areas.

But the latest case differs from the others in that it was considered a “hantavirus infection,” officials said. Although very rare, some hantavirus cases don’t show the respiratory symptoms found in hantavirus pulmonary syndrome, according to the California Department of Public Health.

The eight other cases tied to Yosemite developed into the full-fledged hantavirus pulmonary syndrome.

The person with the hantavirus infection has since recovered, Gediman said. The park received confirmation of the case Thursday morning (Sept. 13).

Spread through urine, droppings or saliva of infected rodents, hantavirus takes one to six weeks before causing flu-like symptoms in humans, officials said. The disease generally is transmitted when people come in contact with an enclosed area that has been infested by mice.

The disease is rare — 587 cases were diagnosed nationwide from 1993 to 2011, of which about one-third were fatal, according to the national Centers for Disease Control and Prevention.

But the cases at Yosemite are more unusual. Public health authorities said they had not heard of more than one case of the disease in the same location within a year.

The newest case was announced a day after Yosemite officials said they were again broadening their outreach efforts, sending emails to some 230,000 people who reserved lodging throughout the park since early June.

“We heard some concerns from visitors, and people read about it in the media, so we felt that we wanted to be proactive and transparent and get the word out to additional overnight visitors,” Gediman said. “We want to get out all the information we can.”

News of the outbreak has rattled visitors, who travel across the globe to the national park. Park rangers have fielded thousands of calls through an emergency hotline. The World Health Organization has issued a global alert, and the U.S. Department of Health and Human Services has notified 39 countries whose citizens were at risk.

Meanwhile, public health authorities and park officials are continuing their investigation into what prompted the outbreak. A larger-than-normal deer mouse population could be a contributing factor, officials said Wednesday.